Key action for musical instrument



Aug. 5, 1958 B. F. MIESSNER KEY ACTION FOR MUSICAL INSTRUMENT OriginalFiled Oct. 3, 1950 7 Sheets-Sheet 1 N WW KN B. F. MIESSNER KEY ACTIONFOR MUSICAL INSTRUMENT Original Filed Oct. 3, 1950 Aug. 5, 1958 7Sheets-Sheet 2 BENJAMIN F. MESS/v55 INVENTOR- T 70/? N Y5 Aug. 5, 1958B. F. MIESSNER 2,845,829

KEY ACTION FOR MUSICAL INSTRUMENT Original Filed 001:. s, 1950 7Sheets-Sheet 3 2/ lmu vli q HEM/A M/N- F. M/ESSNER IN V EN TOR.

' TTORN s Aug. 5, 1958 B. F. MXESSNER 2,845,829

KEY ACTION FOR MUSICAL INSTRUMENT Original Filed Oct. 3, 1950 7Sheets-Sheet 4 I26 /22 I I /23 25 j /2/ /fig [25 f 7% 1 5" BE/VJA MIN/-7 M/ESS/VER I N V EN TOR.

BY 2 %4Q%my M A TOR/V 5 Aug. 5, 1958 B. F. MIESSNER 2,845,829

.KEY ACTION FOR MUSICAL INSTRUMENT Original Filed Oct. 3, 1950 7Sheets-Sheet 5 AMPL TUDE M tom 5 .1.- l5 BE/VJA Ml/V M/ESS/VER I N V ENTOR.

Aug. 5, 1958 B. F. MIESSNER 2,845,829

'KEY ACTION FOR MUSICAL INSTRUMENT Original Filed Oct. 3. 1950 7Sheets-Sheet 6 /5o I7 /52 L /62 A we HEM/A m/v F. M/ESS/VER INVENTOR.

Aug. 5, 1958 B. F. MIESSNER 2,845,829

KEY ACTION FOR MUSICAL INSTRUMENT Original Filed 001:. 3, 1950 7Sheets-Sheet 7 BENJAM/IV F: M/E55/VER 7E -7 INVENTOR.

United States Patent KEY ACTION FOR MUSICAL INSTRUMENT Benjamin F.Miessner, Harding Township, Morris County, N. J., assignor to MiessnerInventions, Inc., Harding Township, Morris County, N. .I., a corporationof New Jersey Continuation of application Serial No. 188,106, October$619550. This application October 28, 1954, Serial No.

6 Claims. (Cl. 84-258) This invention relates to musical instruments andmore particularly to novel arrangement for exciting tuned vibratorsthrough the action of suitable mechanisms controlled by playing keys ofa keyboard.

In musical instruments such as the piano and harpsichord the vibratorsare excited, or set into vibration, by a hammer or a plucker and thevibrations are terminated by separate damper mechanisms upon release ofthe playing key. Additionally, other controls are provided for holdingcertain or all of the dampers away from the tonedamping positions whilestill providing control of the hammer or plucker mechanism through thekeyboard.

In the conventional piano, a hammer strikes a string thereby deflectingthe string at the point of contact. The string deflection is, of course,a maximum at the point of contact with the exciter (referred to as thestriking point) and the amount of string deflection decreases at pointsmore distant from such striking point. The sudden blow sets up alongitudinal wave motion which travels in both directions along thestring, reaches the terminating ends, and is referred back to theopposite ends. Standing waves develop in the string producing nodes andantinodes of vibration.

Another entirely unrelated system of partial vibrations is also set upin the string by the hammer blow. This vibration is of purelylongitudinal type as contrasted with the desired lateral type. Ittravels molecularly along and through the string to both terminations,is there re-' fiected, and so continues back and forth in bothdirections until it finally is damped out. Its frequency is determinedchiefly by the material of which the string is made, the string lengthand, to some extent, by the string tension. While its partial vibrationfrequencies are, unlike those of the lateral vibrations, exactly in tunewith one another, this whole system of partials is totally unrelatedharmonically to the lateral system of partials. Its fundamental pitch isgenerally much higher than that of the lateral system of partials,being, typically, about octaves or so higher and it manifests itself tothe ear as a clang," wolf tone, iron, guts, or etc., terminology wellknown in the art. It is wholly undesirable and has never been eliminatedin the best of pianos.

A third source of sound in such percussively-excited instruments is abroad, continuous band of frequencies, which are heard as noise, due tothe physical impact of the hammer against the string. Where, as in thehigh treble, the hammer strikes the string very close to the bridge, thehammer blow is, in eflect, largely coupled directly to the bridge sothat its noise is like that produced by striking the bridge, or thesound board, or the string frame, directly. Obviously, this sound iswholly unrelated to the desired, lateral vibration tone spectrum offrequencies.

If the hammer, as conventionally employed, is covered thickly with felt,or other resilient material, it will remain in contact with the stringfor some period of time and thus acts as a damper until it is thrownback by the or 2,845,829 1C6 Patented Aug. 5, 195

reaction of the string. This contact time period will vary with themass, kinetic energy, and resiliency of the covering material of thehammer, and with the mass and compliance of the string. In general, thehammer mechanisms are designed to provide variable kinetic energies inthe ranges suitable for the particular strings with which they are used.The hammer mass is made of a low order while the hammer velocity is madefairly high so that the hammer remains in contact with the string foronly a short time interval. The covering material is made variable inresiliency, to some extent, by ironing, needling, or partialimpregnation with thin 'cellulosic cement, as a control of tonebrightness or dullness and for regulating all tones into a smoothprogression of quality.

If the hammer remains in contact with the string for only /2 cycle ofits fundamental frequency, that componentl will suffer only smalldamping-out of its hammerimparted energy of vibration. However, for thesecond vibration partial II the hammer contact time is equal to one fullcycle and, consequently, this partial will sufiier a greater degree ofdamping. The damping increases for vibration partials of higher order sothat the tenth partial X is damped through five cycles of vibration.

Since piano hammers remain in contact with the associated string formuch longer periods than /2 cycle of their fundamental frequency,especially in the high treble region, this hammer damping is a verypronounced factor which governs the harmonic richness of the output toneand also, to a large degree, the tone power or volume. For example, ifthe hammer for string C 88, having a fundamental vibration frequency of4186 cycles per second, remains in contact with the string for a timeperiod of only 0.1 seconds, its damping influence will act on the stringthrough 418.6 cycles of its fundamental frequency (partial I), for 837cycles of its vibration for partial II, 1256 cycles of its vibration forpartial III, and so on. Since this is a typical case, the tones of atensionedstring piano, in the high treble regions, are relativelydeficient in overtones. These tones are also relatively weak. This isdue to the fact that the hammer imparts energy to the string during thefirst cycle after which the string returns considerable of its energy tothe hammer in accelerating the hammer in the reverse direction. Typicalcurves of hammer motion, for high velocity, indicate that the velocityof the hammer as it leaves the string is about 0.8 to 0.9 of itsstriking velocity. Since kinetic energy is equal to MV and the mass M isconstant, the energy returned to the hammer by the string is from 35 toof the energy which the hammer delivers to the string. At low hammervelocities the return percentage is still higher. So it is seen that ofthe total energy delivered to the, keys by the fingers only a relativelysmall percentage remains in the string available for its vibration.Pianos, therefore, require a very considerable amount of work by theperformer in supplying energy, most of which is wasted. Consequently,piano tones, especially in the treble region, are relatively weak andblanketed by the relatively large, wide-band noise frequencies heard ashammer thump, crack, percussive noises, etc., according to variousaccepted descriptive terms.

It may here also be pointed out that if the hammer remains in contactwith the string during more than one cycle of its vibration rate at anyparticular, partial frequency, the frequency of that partial will behigher during the hammer-contact cycles than after the hammer leaves thestring, due to the fact that the hammer acts as a new bridge point forthe string. Under this condition the active length of the string isdivided into two sections, one of which extends from the hammer to thefar bridge and the other of which extends from the hammer to the nearbridge-terminating end.

The tone-terminating dampers, as distinguished from the temporarydamping influence of the exciter-hammers, above described, are separatedevices with very soft, relatively long (axially with respect to thestring) pads. These pads are moved by key depression, from normalstring-contact positions to positions clear ofthe vibrating stringbefore the hammer strikes the strings. Conversely, when the keys arereleased these pads move against the string and quicklydamp-out thestring vibrations.

In the harpsichord a plucking type of vibration exciter is employed. Aplectrum is normally out of contact with the string and when a playingkey is depressed the plectrum rises to touch the string, continuesonward to deflect the string to some fixed maximum deflection when theplectrum suddenly releases the string so that its own built-up potentialenergy causes it to vibrate. While the overall dynamic effects may bevery similar to that of the percussively-excited piano string, however,in the harpsichord arrangement there is no damping of the stringvibrations whatever-by the plectrum exciter which is freed of stringcontact the instant the string oscillation starts. Furthermore, there isno longitudinal system of vibrations (characteristic of hammerexcitation) set up by the plectrum, nor is there produced a broad-bandof noise when the plectrum releases the string. A very low order oflateral string vibrations, at a higher than normal frequency, is setupwhen the plectrum firsttouches the string, but this is inconsequentialand is immediately followed by the very much louder lateral vibrationswhen the string is released.

Contrasted with the piano tone, the tone of the harpsichord is extremelyrich in partial frequencies due chiefly to the absence of the hammerdamping influence. While the dynamic power of a piano tone iscontrollable by velocity of. key depression and the resulting variationof velocity and kinetic energy delivered to the string by the hammer,such characteristic is lacking in the harpsichord. The harpsichord tonesare, therefore, uniformly loud irrespective of the strength or thevelocity of the key blows, similar to those of organ tones. As in thepiano, the harpsichord strings are provided with separate dampers forsilencing the strings when the playing keys are released.

While the piano, due to its'very important touch-responsive, dynamiccontrol of tone, is much preferred over the harpsichord it,nevertheless, possesses many disadvantages such as:

(1) The undesirable damping of the string vibrations by the hammers;

(2) Its unavoidable production of the longitudinal, inharmonicvibrations; and

(3) Its large blanket of impact noises particularly noticed in the upperregister.

The present invention is directed to the provision of a novel andexceedingly simple excitation method and apparatus combining theadvantages of a plectrum and the desirable characteristic of hammerimpact.

An object of this invention is the provision of an excitationarrangement for musical instruments in which the vibrators are excitedby normally deflecting them and then releasing them, whereby thevibrators vibrate due to their own potential energy derived from suchdeflection.

An object of this invention is the provision of a vibrator exciter ofthe key operated type, wherein the vibrator is deflected and thenreleased at varying velocities in response to key-depression velocities,thereby regulating the amplitude of the vibrator vibration.

An object of this invention is the provision of a vibrator-excitingdevice that deflects the vibrator in response to key depression andwhich also serves as a vibration damper for terminating the vibrationsof the vibrator.

An object of this invention is the provision of a keyresponsivemechanism for exciting vibrators which 4 mechanism combines theadvantages of a plectrum exciter and a hammer impact exciter.

An object of this invention is the provision of an exciter-damper devicefor vibrators comprising a resilient member normally deflecting thevibrator from its vibrational axis, and means actuated by a playing keyfor removing the resilient member from the vibrator, whereby the storedpotential energy of the vibrator will set the latter into vibration.

An object of this invention is the provision of a vibrator exciter anddamper comprising a member encircling the vibrator, a resilient padnormally deflecting the vibrator, means for removing the resilient padfrom contact with the vibrator, and means eflective upon such removal ofthe resilient pad to impart a slight plectrum action to the vibrator.

An object of this invention is the provision of an exciter-damper forvibrators comprising a closed frame surrounding the vibrator, arelatively-hard pad of resilient material secured within the frame, avibrator-accommodating opening in the said relatively hard pad, saidopening having a constricted entrance slightly smaller than the width ofthe vibrator, and a pad of relatively soft material secured adjacent tothe first-mentioned pad.

An object of this invention is the provision of a keyresponsive'instrument having tone-producing vibrators, said instrument comprisingkey-actuated exciters for imparting a plectrum action to the vibrators,and for selective damping of the vibrator oscillations, andselectively-operated means for rendering ineffective the damping of thevibrator oscillations. An object of this invention is the provision of amusical instrument comprising a vibrator for tone-generation, anexciter-damper having a normal position wherein said exciter-damperdeflects the vibrator from its vibrational axis, a playing key, meansfor moving the exciter-damper upon key depression, means forming part ofthe exciterdamper for exciting the vibrator upon such key-actuatedmovement of the exciter-damper, and means efiective upon removal of thekey depression for returning the exciter-damper to its normal position.An object of this invention is the provision of a piano whereinexcitation of the tone-generators is accomplished by a novelexciter-damper device and including novel means for providing the loudpedal and sostenuto effects of'a conventional piano,

'An object of this invention is the provision of a novel key-actuatedexciter-damper device for setting a vibrator into vibration incombination with novel means for imparting to said exciter-damper devicea velocity exceeding that of the key depression.

These and other objects and advantages will be apparent from thefollowing description when taken with the accompanying drawingsillustrating several embodiments of the invention. The drawings are forpurposes of illustration and are not to be construed as defining thescope or limits of the invention, reference being had for the latterpurpose to the appended claims.

In the drawings wherein like reference characters denote like parts inthe several views:

Figure l is a fragmentary, side-view of a tensionedstring piano, withcertain parts in cross-section, and illustrating the general arrangementof the parts in an instrument made in accordance with this invention;

Figure 2 is a cross-sectional view taken along the line A-A of Figure 1and drawn to an enlarged scale to show the construction of one form ofmy exciter-damper device;

Figure 3 is similar to Figure 2 and showing another construction of theexciter-damper for imparting a slight amount of plectrum action to thetensioned string;

Figure 4 is a cross-sectional view taken along the line B-B of Figure 3and illustrates the normal, deflected position of the tensioned string;

Figure 5 is a fragmentary view, similar to Figure 3,

showing the vibration of the tensioned-string upon excitation by thevibration damper;

Figure 6 is a fragmentary view, similar to Figure 3, but showing anexciter-damper designed for use with a vibratory reed;

Figure 7 is similar to Figure 6 illustrating the vibration of the reedupon excitation by the exciter-damper;

Figures 8 and 9 are fragmentary, side views, with certain parts incross-section, showing an arrangement for obtaining the sostenuto eifectin an instrument provided with my novel exciter-damper;

Figures 10 to 12 illustrate an arrangement for continuing the vibrationsof excited vibrators even though the playing key has been released, thiseffect corresponding to the loud pedal effect of a piano;

Figure 13 illustrates another arrangement for obtaining the effectprovided by the construction shown in Figures 10 to 12;

Figure 14 are curves showing relative string vibration and the motionalvelocity of the exciter-damper to produce string vibration of maximumamplitude;

Figure 15 illustrates a lever-arm and hammer arrangement for increasingthe motional velocity of the exciterdamper in response to a relativelylower key-depression velocity;

Figure 16 is somewhat similar to Figure 15 but in this case theexciter-damper responds directly to movement of the playing key, whereasin the Figure 15 arrangement movement of the exciter-damper is theresult of an impact force;

Figure 17 is also somewhat similar to Figure 15 but showing a differentarrangement of the lever arm;

Figure 18 is a side view, with certain parts in crosssection, of asimplified exciter-darnper device;

Figure 19 is a cross-sectional view taken along the line A-A of Figure17.

Figure 20 is a fragmentary front view showing a novel arrangement forretaining the struck playing keys in the depressed position to therebyhold the eXciter-damper device clear of the vibratory string; and

Figures 21, 22 and 23 are sectional views taken along the lines AA, BBand CC, respectively, of Figure 20.

While I shall describe my novel exciter-damper device specifically withrespect to a string type vibrator, it will be apparent that it isequally applicable to and useful with other vibrators of readilyyieldable type such as reeds, thin rods, etc. The novel exciter, whilefully capable of exciting maximum vibrations in a string or othervibrator, acts in a reverse manner to that of hammers and somewhatsimilar to a plectrum. Unlike the hammer, however, which introduces itsenergy into the normally-undeflected string very rapidly by percussion,my exciter introduces energy relatively slowly into the string andstores it there as potential energy for the normal condition ready atall times for instant release on key depression. It is, therefore, quitethe opposite of the percussion type of excitation. In fact, it is morelike the plectrum action in that it deflects the string and releases it.The deflection is relatively slow and instead of rapidly deflecting andreleasing the normally undeflected string in one rapid sequence ofoperations, the exciter slowly deflects the string for the normalcondition and releases it more or less rapidly when the playing key ofthe keyboard is depressed so that there is a notable and importantdistinction in method and apparatus. Additionally, I may utilize thestring deflector as a tone-terminating damper. By these means I providean extremely simple and inexpensive exciter and damper for string, orother flexible, vibrators.

For electronic instruments utilizing strings, reeds, etc., thisnormally-deflected vibrator principle olfers an important advantagesince the spaced capacitive or other pick-up device may be so placedthat the spacing between such pick-up and the vibrator is relativelylarge. By this 6 arrangement the normal capacity between a group ofvibrators and pick-ups is much reduced. This normal capacity determinesthe amount of modulation (of the total capacity) producible by a singlevibrator and pickup electrode, and this, therefore, determines thetranslation etliciency. For example, if 88 vibrator reeds and theirclosely-spaced, end wise pick-ups have an aggregate capacity of 500mmf., vibration of one of the reeds at any maximum amplitude (includingremoval of the reed entirely) could change only 1/88 of the totalcapacity. If, however, all reeds are normally deflected from theirassociated, axially-positioned pick-ups by an amount equal to themaximum desired vibration amplitude, the normal capacity between allreeds and pick-ups may be reduced to the order of 1% or less of theassumed aggregate capacity of 500 mmf. or to a total capacity of only 5mmf. Since the maximum capacity of each reed and pick-up is 500/88:5.68mmf., and since the residual capacity of all the parallel-connectedreeds and pick-ups is 5 mmf., it is seen that the capacity modulation ofthe total capacity produced by a single reed, at the assumed maximumvibration amplitude, would vary this capacity between a minimum of 5mmf. and a maximum of 10.68 mmf., thus yielding a capacity modulation ofover 50%. In the first mentioned, conventional arrangement, themodulation is only 1 part in 88 or about 1.4%. The translatingefliciency of the normally-deflected vibrator excitation system, as willbe described in detail hereinbelow, is, therefore, 50/ 14 or 35 times asgreat as that for percussively or plectrum excited vibrators withsimilarly located pick-ups.

Referring now to Figure 1, there is shown a side view, with certainparts omitted and others drawn in crosssection, illustrating the generalarrangement of the parts in a piano made in accordance with thisinvention. The instrument may be housed in a cabinet comprising a base20, a lid 21, a slidably-removable front board 22, and a back (notshown), said cabinet being supported by suitable legs 23 provided withcastors 24, as is common in piano construction. The keyboard of theinstrument is of the conventional type and includes a series of keyssuch as the key 25. Each key is retained in position by a pivot pin 26extending upwardly from the base 20 and passing through a tapered holein the key, substantially as shown. Smooth, rocking motion of the key,in response to linger pressure applied to the outer end thereof, isprovided by a curved pivot rail 27 spaced from the key by a resilientwasher 28. Excessive lateral motion of the key is prevented by the keyguide pin 29 that is secured to the base 20 and extends into a bore inthe key. The pad 3t) serves to limit the downward motion of the key andto deaden the contact noise when the key is depressed vigorously. A woodstrip 31, secured to the cabinet base by a screw 32, prevents theentrance of foreign objects between the key and the base and alsoenhances the general appearance of the instrument. The inner end of thekey has a resilient pad 33 secured thereto, as by cement, which padcooperates with a similar pad 34 secured to the base to preventrebounding of the key as it returns to its normal position.Alternatively, only the pad 34 comprising a long, continuous strip forall the playing keys, need be used, as in a conventional piano.

The tensioned-string 39 is stretched across a rather massive iron stringframe 40, one end of the string being fastened to a string hitch pin 41and the other end entwined around the tuning pin 42, said pin beingthreaded into the iron frame. A fixed bridge 43 secured to the frame 40and a bridge 44 carrying the bridge pins 45, establish the effectivelength of the string. The bridge 44 is supported by and in direct gluedcontact with the sound board 46, whereby vibrations of the string areimparted to the sound board to produce an audible tone, as is wellknown. As in conventional practice, .the sound board is arched betweenheavy board planks 47, 48 the latter being rigidly secured to the ironframe 40 and .through offset, end-sections of. each. Cemented to theinner surface of the upper member 50 is a pad 54 of resilient material,such as felt, sponge rubber or, etc., said pad being provided with atriangular opening, substantially as shown, for accommodation of thestring 39. The threaded rod 55, having a head 56 on one end, passesthrough a hole in the guide rail 57 and the sound board 46, and isthreaded into the lower, curved member 51. It may here be pointed outthe guide rail 57 extends substantially the entire width of the pianoand is secured firmly in a fixed position below the sound board 46. Thehelical spring 58, disposed between the guide rail and the rod head 56serves to bias the entire exciterdamper downwardly so that the nut 60 isin contact with the resilient pad 61 carried by the guide rail 57.Consequently, when the playing key is in the normal position, as shownin Figure 1, the string 39 is engaged by the pad 54 and the string,therefore, is deflected from its otherwise normal, straight position.The maximum downward normal deflection of the string may be regulated bythe nut 60 threaded on the rod 55, said nut seating on a resilient pad61 secured to the upper surface of the guide rail 57. When the playingkey is struck the entire exciter-damper moves upward, thereby removingthe string-deflecting pressure and allowing the string to vibrate. Afterkey depression and initiation of string vibration, release of theplaying key results in a downward motion of the exciter-damper, underthe action of the coiled spring 58, whereby the V-shaped pad 54 isbrought into contact with the string 39 thus terminating the stringvibration and again deflecting the string in preparation for asubsequent depression of the playing key.

The above described arrangement is suitable only for strings andvibrators of relatively low frequency and for low to moderate vibrationamplitude since the maximum velocity of removal of the exciter-damperdevice is limited to the maximum velocity of key depression.

An adaptation of the same general principle for more general applicationcan be accomplished by providing a small amount of plectrum action whenthe string is excited into vibration. Such plectrum action, incombination with the normal deflection pressure on the vibrator,provides a certain minimum of vibrator vibration irrespective of thevelocity of key depression. Performance somewhat of this character isachieved in the plectrum action of the harpsichord, but at the expenseof an undesired, uniformly-loud output tone at all velocities of keydepression. In my novel arrangement the amount of plectrum excitation isvery small and just suflicient to produce a very low minimum amplitudeof vibration for each complete key depression. Such performance is neverattained in piano actions at key depression velocities below a set,appreciable minimum so that in the rendition of pianissimo passages eventhe best artists frequently have blank tones due to too low depressionvelocity.

An exciter-damper arrangement incorporating a small amount of plectrumaction is illustrated in Figures 3 to 5. Figure 3 is somewhat similar toFigure 2. In this case, however, the looped exciter-damper is formed oftwo strips 70, 71, of metal or plastic. The curved portions of the metalstrips are secured together by a screw 72 and nut 73 while the lower,flat portions may be secured together as by welding at the points a, band c. The ends of the strips are offset at right angles to provide thehead 74 that bears against the resilient pad 59 carried by the playingkey (Figure 1). This head also serves to support a flat felt washer 75and the coiled spring 76 is retained between this washer and a similarwasher 77 that abuts against the lower surface of the guide rail 57. Aportion of the edges of the straight section of the strips 70, 71 isprovided with a thread for accommodation of the regulating nut 78 thatseats against the resilient pad 79 and serves the purpose explainedabove with reference to the nut 60 of Figures 1 and 2.

Cemented to the inner surface of the loop formed by the strips 70, 71 isa member 80 of hard felt or soft rubber and having a circular opening 81therein said opening lying on the center line of the loop. This opening81 is slightly larger in diameter than the vibratory string 39, but itsdimension across the opening in the arcuate face of the member 80 isslightly less than the string diameter. Hence a definite small amount ofpressure is required to force the string 39 into and out of the opening81. Two arcuate members 82, 83, of relatively resileiut material, suchas soft felt, are cemented within the loop and to the member 80. Thesemembers are spaced to clear the opening to the circular opening 81 inthe relatively hard member 80. As shown in Figure 4, which is a centralcross-sectional view taken along the line B-B of Figure 3, therelatively soft and wide members 82 and 83 have a dimension along thestring axis which is fairly long so that these members damp the stringalong an appreciable portion of its length when i the playing key isreleased, as in conventional piano dampers. This prevents a sharp lineof division of the string into two segments. The relatively hard member80, however, is relatively short along the string axis to providedefinite such string segments.

In the Figure 3 illustration the exciter-damper is shown in its normalat-rest position and the string 39 lies within the opening 81. In thisposition of the exciter-damper device the string is deflected downwarddue to the action of the coiled spring 76. When the playing key isdepressed the exciter-damper is raised relative to the string. Untilsuch time as the string returns to its striaght line position nothinghappens. However, as the exciter-damper continues to move upward beyondthis point the string tends to leave the opening 81. However, since theentrance of this opening is slightly less than the string diameter, asmall upward deflection is imparted to the string before it slipsthrough this opening into the relatively large clearance area 85 withinthe loop. Although the material of the member 80 is yieldable it issufiiciently rigid to impart a slight plectrum action to the string asthe latter snaps through the narrow passageway between the opening 81and the clearance area. In other words, the member 80 has sufficientradial yield to allow the string to pass into and out of the hole 81 andsufficient stiffness to hold the string there against the smalldeflecting force acting upon the string as the device is moved upward.

Once the string 39 snaps out of the opening 81 it is set into vibration.It will be apparent that at low key depression velocity the plectrumaction imparted to the string as it leaves the opening in the member 80is very small and, consequently, the string vibration amplitude issmall. The clearance area 85 is designed so that the string will notcome into contact with any part of the exciter-damper at maximumvibration amplitudes in either the vertical, horizontal or orbitalmodes. This is shown in the fragmentary view of Figure 5 wherein themaximum vibration of the string 39, in all planes, falls within thedotted line 86.

When the playing key is now released the exciterdamper moves downwardunder the action of the coiled spring 76. The vibrating string vibratesinto contact 9 with the resilient, relatively-soft pads 82, 83 whichdamps the string vibration. At the termination of the string vibrationthe string is forced through the passageway between the member 82, 83and into the circular opening 81 where it comes to rest as theexciter-damper descends further. It will be understood that the lower,soft-material pads 82, 83 are relied upon for damping the stringvibration to substantially zero before the string enters the slotaperture and that no biasing deflection of the string is producedthereby. If such biasing deflection occurred while the string is stillvibrating the frequency of the string vibration would be increased asthis damper would act momentarily as a new bridge point therebyeffectively shortening the vibration length of the string.

When the exciter-damper is made of strip material as described withreference to Figures 35, the hole 90 in the guide rail 57 may have arectangular form corresponding to the cross-sectional form of the shankportion of the exciter-damper. In such arrangement there can be nosubstantial turning of the exciter-damper and, therefore, a properpositioning of the device with respect to the string is maintained atall times. To promote smooth, noise-free action, the rectangular hole inthe guide rail may be lined with felt 91.

The exciter-damper device is adapted for use with other thantensioned-string vibrators. Figures 6 and 7 which are fragmentary viewsshowing only the upper portion of the device, show an exciter-damperdesigned for use with vibratory reeds. Here the loop may be formed byjoining together strips 100, and 101 in a manner similar to thatdescribed with reference to Figure 3. The upper, relatively hard pad 102has a constricted opening 103 therein, the length of said opening beingslightly less than the width of the flat reed 104. Soft pads 105, 106 ofvibration damping material are cemented to the pad 102 and to the innersurface of the strips 100, 101, substantially as shown. As theexciter-damper is raised, in response to depression of the playing key,the reed snaps through the constricted passageway into the clearancearea 107, the latter being of a size to permit unrestricted, maximumvibration of the reed, as shown by the solid and dotted reed positionsin Figure 7.

As has been stated above, the normally-deflected vibrator principle isvery advantageous in electronic musical instruments, wherein thevibrator vibrations are translated into musical tones by means ofcapacitive pick-up and associated translating, amplifying andelectro-acoustic apparatus. Inasmuch as the vibrator normally isdeflected from its vibrational axis, the aggregate capacity of allvibrators and associated pick-ups is materially reduced since suchpick-ups are best located in line with such vibrational axis. Also, whenthe exciter-damper device releases the vibrator (thereby exciting thevibrator into vibrations about its longitudinal axis), the capacitybetween the vibrator and its pick-up increases considerably.

Consequently, the modulation of the total capacity, by vibration of asingle vibrator, is substantially greater than s possible in theconventional arrangement wherein the at-rest position of the vibratornormally corresponds to the axis about which the vibrator vibrates uponexcitation. Therefore, it is apparent the excitation of the vibrators bythe novel means herein described results'in a greatly increasedtranslation efficiency of the electronic apparatus as a whole.

My novel exciter-damper arrangement also lends itself to mechanicalcombinations affording playing techniques corresponding to those of theconventional piano. A simple arrangement may be provided to hold theexciter-damper in the upper position, after tone excitation, withoutcontinued pressure on the playing key. Such operation, set into effectby a foot-operated pedal, corresponds to the sostenuto control used ingrand pianos.

Figure 8 is a fragmentary view, similar to Figure 1, illustrating asimple arrangement for obtaining the sostenuto effect. Theexciter-damper device is constructed as shown in Figures 3 and 4, butonly the lower portion thereof is shown in Figure 8. Such lower portioncomprises the straight sections of the strips 70, 71 together with thecoiled spring 76 having an end abutting against the fiat washer 75 thatis retained by the offset end sections of the members 70, 71. Whereas,on the Figure 3 embodiment these offset end sections are of equal lengthto provide the leg or base 74 (Figure 3), in the Figure 8 constructionthe offset section 106 of the strip 71 is made somewhat longer to extendbeyond the end of the playing key 25. Disposed above the section 106 isa slide plate 107 that is slidably secured to a fixed rail 108 by thescrew 109 and the flat washer 110. It may here by pointed out that thefixed rail 108 extends across the full complement of playing keys asdoes also the slide plate 107. This slide plate is normally biased awayfrom the exciter-damper devices by a series of coiled springs. One suchspring 111, having its ends secured to an eye bolt 112 carried by theplate 107 and an eye bolt 113 carried by the fixed member 108, is shownin the Figure 8 illustration. Horizontal movement of the slide plate isaccomplished by depression of the pivoted foot-pedal 114, the latterbeing connected to the eye bolt of the slide plate by a cord 115operating in the pulley 116. As shown in Figure 8, the slide platenormally is biased by the springs 111 so that the edge of said platelies clear of the edge of the leg 106 of the exciterdamper and,consequently, the latter is free to move vertically in response todepression of the playing key in the normal manner. When the sostenutoeffect is desired the playing keys corresponding to the desired musicalchord are depressed and held momentarily until the footpedal 114 ispressed downward. This condition is shown in Figure 9 wherein operationof the foot-pedal has moved the slide plate 107 so that its forward edgelies below the leg 106 of the exciter-damper. When the playing keys arereleased, while maintaining the foot-pedal in the depressed position,the legs 106 of the actuated exciterdampers will rest upon the slideplate 107 and in this position of the exciter-damper the string is freefor unrestricted vibration, as shown and described with reference toFigure 5 above. Such string, or strings, continue vibrating so long asthe foot-pedal is held down until, of course, the vibrations terminatein a natural manner. Upon release of the foot-pedal the slide platemoves to the right under the action of the coiled springs, therebyallowing the exciter-dampers to return to the normal position wherebythe string vibrations are damped and the string is placed in thenormally-deflected position as described hereinabove.

An arrangement for producing, in this apparatus, the loud pedal elfectof a conventional piano is illustrated in Figures 10 to 12. Here a fixedrail 120, that may be secured to the bottom 20 of the cabinet, extendsthe full length of the entire complement of playing keys. A slide plate121 having a length corresponding to the rail '120 is slidable on thetop surface of the said rail being secured to the latter by a series ofscrews 122 and washers 123. The slots through which the screws passthrough the slide rail are elongated thereby providing stops to limitthe horizontal, sliding movement of the plate 121. In the normal,ineffective position, the slide plate 121 occupies the position shown inFigure 10 being biased to the right by a series of leaf springs 124secured to the fixed rail by the screws 125. In this position the edgeof the slide plate lies spaced from the vertical line of travel of aflat spring 126 that is attached to the leg extension 106 of theexciter-damper. The leaf spring 120 which may be attached to the legextension 106 as by welding at the point d, forms a flexible arm whichis free to move downward relative to the extension 106, but cannot moveupward because its length is materially reduced by the overlapping ofthe extension 106, as will become more apparent hereinbelow.

When the slide plate 121 occupies its normal position,

11 Figure. 10, the entire exciter-damper is free to move vertically,that is, upward in response to depression of the playing key anddownward under the action of the coiled spring 76 (see Figure 1) whenthe playing key is released. The slide plate 121 may be moved to theleft (toward the exciter-damper) by a pedal action similar to thatdescribed with reference to Figures 8 and 9, such mechanism beingomitted from Figures lO-12 for purposes of clarity. When the slide plate121 is so moved to the left its forward edge crosses the vertical lineformed by edge of the spring 126 as it moves upward and downward withthe exciter-damper. Thus, when the exciter-damper is raised, in responseto depression of the playing key, the leaf spring 126 contacts the lowersurface of the slide plate 121 and is bent downwardly, as shown inFigure 11. In this direction of flexure the spring 126 hasa relativelylong, effective length and, therefore, it deflects downwardly (away fromthe extension 106) quite readily. Such deflection of this springcontinues as the exciter-damper moves further upward until the saidspring snaps past and over the slide plate 121. Now, when the playingkey is released, as shown in Figure 12, the exciter-darnper is held upby the spring 126 resting on the upper surface of the slide plate 121.In this position of the exciter-damper the vibratory string is free tovibrate as shown in Figure 5. When the footpedal is released, thesprings 124 move the slide plate 121 tinuance of all tones which havebeen started by key depression but will not permit a re-excitation ofthese particular strings until the loud pedal is released. Thus, aseries of tones, say a long arpeggio of harmonically-related tones, maybe sounded and held, while other tones are played, without undamping allthe strings of the instrument, as is the case in a conventional piano.When the sustaining or loud pedal of a conventional piano is depressedevery string in the instrument is free to vibrate as such action removesall the tone dampers. Therefore, any struck strings may communicatetheir vibrations to other strings by resonance action through themechanical coupling of the bridge and sound board. Furthermore, since avery appreciable part of the hammer impact is coupled directly into thebridge as an impulse, this sets all strings into vibration, especiallythose close to the struck strings since here the degree of coupling isthe greatest- Thus, when a number of strings (throughout the compass ofthe instrument) are struck, every string in the instrument iseffectively, impulsively excited by the shocks communicated to thebridge at various points. The resulting complex sound takes on a strongcharacteristic of noise, which is merely a broad, continuous band offrequencies. Additionally, of course, the struck strings, which receiveconsiderably more energy from their hammers than do the large number ofother, unstruck strings, vibrate at a greater amplitude so that thetones of these strings stand out above the general noise level of allthe unstruck strings, at least so long as their amplitude of vibrationis high. This excitation of the undamped, unstruck strings serves noreal musical purpose. It produces only a strong background of roaringnoise which blankets the desired tones.

The arrangement which I have just described, therefore, produces muchbetter musical results than does the conventional sustaining pedal ofthe piano. Its only limitation, not found in the conventional piano, isthat strings once struck cannot be restruck until the sustaining pedalhas been released (slide-plate 121 removed to its right hand position asshown in Figure 10). This is not considered of serious importance inview of the other advantages.

Figure 13 is similar to Figure 11 but shows a different arrangement ofthe flexible leaf spring for obtaining the sustaining or loud pedaleffect. In this case the leaf spring 126' is secured to the uppersurface of the slide plate 121 instead of the leg extension 106 of theexciterdamper and the general action of the apparatus is similar to thatdescribed with reference to Figures 10-12.

As previously mentioned, the complete apparatusdescribed to this pointis useful in connection with vibrators that vibrate at relatively lowvelocity, at least at that part of the vibrator Where the exciter-damperis applied. Since strings, or clamped-free reeds, have a zero meanvelocity at their fixed ends, it is desirable that these exciter-damperdevices be applied at points relatively close to such vibrator ends.However, the degree of pressure required at such points for theproduction of the desired maximum amplitude of vibration is greater thanat points further along the vibrator, that is, at the free end ofclamped-free vibrators and at the center of tensioned strings. Since thepressure of the spring, which maintains the exciter-damper and thevibratory string in a normally-deflected position, must be overcome bythe playing key, and since it may be desirable (particularly forhigh-velocity vibrations of the higher pitched vibrators) to providehigher velocities of release of the stringdeforming exciter-damper, itmay be desirable to utilize a velocity step-up lever arrangement toaccomplish these ends.

In order to realize an amplitude of string vibration equal to theamplitude of deflection at the point of application of such deflectingforce, the deflecting device must be removed at a velocity at leastequal to or slightly in excess of the velocity of the string throughone-half /z) of its vibration cycle, such cycle beginning at a point ofmaximum amplitude. This will be clear by reference to Figure 14. If thestring be normally deflected downward by the excited-damper to anamplitude of minus ten (10) units and if it be desired to vibrate thestring initially at this amplitude at the point of stringdeflection, thestring-deflecting exciter must move away from the string at a velocityat least as great (and preferably slightly greater) than theunrestrained string velocity. The unrestricted string velocity variesalong the String Vibration Curve from zero velocity at the point C to amaximum velocity at the point D, the velocity reducing thereafter,during the first half cycle of vibration, to zero at the point E.Consequently, the exciterdamper should have a motional characteristiccorreponding substantially to the curve identified as Exciter- DamperCurve on Figure 14. Point E, for damped oscillations, will always have alower amplitude than the starting amplitude at point C, the actualdifference being determined by the various damping influences acting onthe string, such as air damping, physical hysteresis losses of thestring, losses at the string end supports, losses in the bridge andsound board, sound radiation losses, etc.

If the frequency of vibration of the string he, say, 500 cycles persecond and the peak amplitude of the maximum vibration be 0.1 inch, thestring will move from point C, through point D, to point B, a distanceof approximately 0.2 inch in of a second with an average velocity of 200inches per second. This, by actual measurement, is the terminal velocity(as the hammer begins string contact) of a relatively large bass typepiano hammer, at maximum velocity, as produced by a very strong key blowthrough a step-up lever motion between the key and the hammer head ofapproximately 5 to 1. High treble-range hammers of lighter weight mayhave terminal velocities of 40050O inches per second. The maximumterminal velocity of the playing key is of the order of /s of thesevelocities or only 40 to inches per second which is too low for usedirectly in the exciter-dam-per arrangement herein described when usedat some appreciable distance from the fixed end of a vibrator, and whenthe vibrator must be vibrated 13 at large amplitudes of vibration.rangement, therefore, is provided.

The step-up lever arrangement may have a mass considerably in excess ofthat of the exciter-damper assembly in order that the exciter-damper maybe accelerated very rapidly without appreciably lowering the velocity ofthe lever arrangement. The exciter-damper device is, therefore,preferably made as light in weight as practicable while retainingsufficient vertical stiffness to absorb a hammers accelerating forceswithout appreciable deformation.

Figure 15 illustrates an arrangement of a step-up lever arrangement forattaining high-velocity release of the string-deflecting,exciter-damper. The arrangements for the sostenuto and sustaining pedaleffects are omitted for the sake of simplicity. This particulararrangement includes a weight at the end of the lever arm for rapidlyaccelerating the eXciter-damper although such weight is not essential tothe operation of the arrangement, as will become apparent hereinbelow.The vibratory string 39, its attaching members and the associatedcomponents, are the same as shown in Figure 1 and the exciterdamperdevice is identified by the numeral 130. The lever action comprises anarm 131 pivotally attached to the flange 132 that is secured to a fixedhammer rail 133 by a screw 134. A weight 135, having a soft pad 136thereon, is attached to the free end of the arm 131, whereby the armnormally rests upon a soft pad 137 affixed to a block 138 supported bythe cabinet base 20. In this arrangement the inner end of the playingkey 25 carries a capstan screw 139 adjusted for normal contact with apad 140 aifixed to the pivoted portion of the arm 131, as shown. Whenthe playing key is depressed the arm 131 is rotated in acounter-clockwise direction and the weight 135 strikes the head 56 ofthe exciter-damper device causing the latter to move upward and therebyexcite the string 39 into vibration, as has already been explained. Itwill be apparent the velocity-multiplying action of the mechanism isdetermined by the ratio of the distances of the weight 135 and thecapstan screw 139 from the pivot point 143 of the arm 131. Consequently,the weight 135 strikes the ex-citer-damper device at a velocitysubstantially greater than that of the key depression.

Figure 16 illustrates a similar lever action. In this case the weightcarried by the striker arm is dispensed with and the end of the leverarm 131 normally is in contact with the head 56 of the exciter-damper,through the medium of a soft pad 141. This is accomplished by making thesupporting rail 142 of proper height. Figure 16 also illustrates amodified construction wherein the sound board 46 terminates in a heavysupporting member 145 which also serves as the guide rail for thesupport of the exciter-damper devices, substantially as shown.

Figure 17 illustrates a lever arrangement that is more economical ofspace since the lever arm 131, its supporting members, and approximatelyone-half of the playing key 25 are telescoped under the string 39. Insuch arrangement the end of the lever arm rests upon a pad 146 afiixedto the upper surface of the playing key at a point near the keypivot-pin 26. At the moment of key depression the lever arm is set intomotion by forces applied by the capstan screw 139 and the key pad 146.

This arrangement is effective to overcome, in the initial instance, theinertia of the lever arm and the exciterdamper, after which anaccelerating velocity is imparted to exciter-damper by the multiplyingaction of the mechanism through the capstan screw. The height of thesupporting post 148, carried by the key frame 149 is such that theentire assembly of keys, lever arms, etc., may slidably be removed fromthe front of the piano after the front panel 22 has been removed and theexciterdamper assembly has been unscrewed, as a whole, from thesupporting member 150. For this purpose, the guide A step-up leverarrail 151, supporting the series of exciter-damper devices, is securedto the sound board support by screws 152 that are located between theeXciter-dampers.

From the description to this point it will be apparent mynormally-deflected vibrator arrangement operates on a principle whichhas not been applied, within my knowledge, to instruments of the typeemploying vibrators for tone generation, and which offers many uniqueadvantages. While the exciter-damper arrangement employing a slightamount of plectrum action is preferred, the simple vibrator deflectorand release arrangement, as described with reference to Figure 2, issatisfactory for use in instruments in which there is imparted a certainminimum velocity to the playing keys. It is especially suitable for theexcitation of vibrators having small physical dimensions, such as thoseunsuited for direct, acoustic tone production, but which are highlysuitable for use with electronic devices for translating their m1 nutevibrations into musical tones of ample power. In such instruments butsmall deflecting forces are required and small normal key depressionforces are ample for counteracting the vibrator-deflecting forces.

Figures 18 and 19 illustrate a somewhat simplified arrangement forapplying a vibrator-deflecting force that is removable upon keydepression whereby the vibrator is set into vibration by its storedpotential energy. As in the Figure 2 device, the velocity of removal ofthis normal deflecting force determines the amplitude of vibra tion sothat this device is fully touch responsive in key operation, being quitesensitive to low velocities of key depression and producing graduallyincreasing vibration amplitudes up to the amplitude of reed deflectionproduced by the exciter-damper deflecting force. As shown in Figures 18,19, the exciter-damper comprises an L- shaped rod having a threaded endscrewed into the playing key 161. The other end of the rod carries atube 162, made of rubber, felt or leather, that may be secured theretoby cement. The inner end of the playing key has a weight .163 securedthereto by a screw 164, said weight serving to retain the playing key inthe normal position as shown in Figure 18. The vertical length of therod 160 is such that when the playing key is in the normal position thetube 162 deflects the vibratory reed 165 from its normal, straightposition, said reed being secured to a reed block 166 as by the plate167 and the screw 1158. Upon depression of the outer end of the playingkey the reed deflecting force is removed and the stored potential energyof the reed sets the reed into vibration, it being apparent the reedvibration amplitude is determined by the velocity of key depression,that is, the velocity of removal of the exciter-damper from contact withthe reed. Upward movement of the inner end of the playing key is limitedby a key stop comprising a bracket 170 secured to the key frame 171 bythe screw 172, said bracket having a resilient pad 173 secured theretofor contact by the similar pad 174 affixed to the key 161, as shown.Upon removal of key depression the exciter-darnper returns to its normalreeddeflecting position whereupon the tube 162 contacts the uppersurface of the reed, terminating the reed vibrations and again placingthe reed in the deflected, stored-energy position ready for thesubsequent key depression.

Figures 20 to 23 illustrate a novel arrangement for retaining a struckplaying key in the depressed position to permit unrestricted vibrationof the associated vibrator. In Figure 20, which is a fragmentary, frontview of a piano, the playing keys 1% and 132. are shown in the normalposition, While the playing key 181 is shown in the depressed position.Disposed in front of each key is a flat leaf spring, such as the springs183, 184 and 185, which are secured at the lower ends to a slide rail186 by the rivets 187, or other suitable means.

As shown in Figure 21, which is a sectional view taken along the lineA-A of Figure 20, each leaf spring, in this case the spring 183, has ahead 189 and the slide 15 rail 186 is slidable in a slot 190 thatextends the full width of the base 191. The slide rail 186 normally isbiased to the left by a compression'spring 192 whereby the leaf springsnormally are spaced so. the heads thereof do not interfere with thenormal operation of the playing keys, as shown.

When the slide rail 186 is moved to the right, as shown in Figure 22which is a sectional view taken along the line BB of Figure 20, the leafsprings (spring 184 in this case) are brought up against the front faceof the base 191 in which position the heads (189 in this case) overlythe front edge of the associated playing keys (181 in this case).Consequently, when the playing key is now depressed the associated leafspring will latch the playing key in the depressed position and such keywill be so held until the slide rail 186 is again moved to the left toremove the leaf spring head (and all others) from contact with theplaying keys.

The position of the slide rail 186 may be controlled selectively by theartist by means of a foot pedal; As shown in Figure 23, which is asectional view taken along the line CC of Figure 20, the foot pedal 195is pivoted at the inner end 196. A cord 197, or chain, is securedbetween the foot pedal and the slide plate 186, said cord passing over apulley 198 that is mounted in an opening 199 provided for this purposein the base 191. When the pedal 195 is in the normal position, as shoswnin Figure 23, the slide rail 136 is biased to the left by thecompression springs 192 of which there are several disposed behind theslide rail at spaced points along the range of the keyboard. When thepedal is pressed downward the slide rail 186 is moved to its activeposition, as shown in Figure 22, wherein the individual leaf springswill catch such playing keys as are depressed. From what has beenexplained hereinabove with respect to the operation of theexciter-damper device, it will be apparent that when one or more of theplaying keys are retained in the depressed position the correspondingexciter-dampers will remain in a position wherein the associated stringsare free to vibrate in the natural, undamped manner. Release of the footpedal removes the latching leaf springs, whereupon the playing keysreturn to the normal position permitting the exciter-damper to terminatethe string vibration, as has been explained.

A unique advantage of the key-latching arrangement just described is thefact that there is provided a visual indication by the depressed key, ofthe strings, or vibrators, that cannot be re-excited until the latchingmechanism is released.

From the above described invention those skilled in this art willrecognize the following advantages of my exciter-damper arrangement forexciting a vibrator into vibration and for terminating such vibrations:

l) I eliminate the damping by the exciter device after imitiation of thevibration,

(2) I eliminate the longitudinal vibrations produced by percussiveexciters,

(3) I eliminate the broad band spectrum of noise frequencies produced byhammer excitation,

(4) I retain the full spectrum of string frequencies as with theplectrum exciter,

(5) I retain a full control of tonal dynamics through control of thevelocity of key depression,

(6) I utilize the exciter device as a tone-terminating damper.

These and other advantages are secured with an extremely simple,reliable and inexpensive mechanism which requires no intricate devicesfor the prevention of multiple string excitation for single key blows,and will operate at extremely low or high speeds. The dynamic resistanceto key depression, caused by the necessarily very rapid acceleration ofrelatively large masses in conventional percussively-excited systems isherein greatly reduced, so that much less effort is required of thefingers in playing the instrument,

Having now described my invention in detail in accordance with thepatent statutes, various changes and modifications will suggestthemselves to those skilled in this art, and it is intended that suchchanges and modifications shall fall within the spirit and scope of theinvention as recited in the following claims. I

Thisapplication is a continuation of my co-pending application SerialNo. 188,106, filed October 3, 1950, now abandoned.

I claim:

1. In a musical instrument, the combination of a vibrator, meansnormally deflecting the vibrator from its vibrational-mean position, aplaying key, and means effective upon actuation of the playing key formoving said deflecting means away from its vibrator-deflecting position,said deflecting means comprising a member formed into a loopcircumscribing the vibrator, a resilient pad within the loop and anopening in said pad, said opening being sufficiently large toaccommodate the vibrator but the entrance thereto being smaller than thedimension of the vibrator transverse to the direction of movement of thedeflecting means.

2. In a musical instrument, the combination of a vibrator, a dampernormally contacting and damping the vibrator, a support carrying thedamper and arranged for movement to remove the damper from the vibrator,and means, also carried by said support, effective in saiddamper-removing movement of the support to engage and deflect thevibrator and thereafter to release the sodeflected vibrator.

3. In a musical instrument, the combination of a vibrator, a dampernormally contacting and damping the vibrator and deflecting it from itsvibrational-mean position, a support carrying the damper and arrangedfor movement to remove the damper from the vibrator, and means, alsocarried by said support, effective in said damper-removing movement ofthe support to engage and deflect the vibrator and thereafter to releasethe sodeflected vibrator.

4. In a musical instrument, the combination of a vibrator, a dampernormally contacting and damping the vibrator, a support carrying thedamper and arranged for movement to remove the damper from the vibrator,and a pair of yieldable jaws also carried by said support and moved bythe support, in said movement thereof, past the vibrator, said jawsbeing separated by less than the dimension of the vibrator transverse tothe direction of said movement whereby to pluck the vibrator during saidmovement.

5. In a musical instrument, the combination of a vibrator, a dampernormally contacting and damping the vibrator and deflecting it from itsvibrational-mean position, a support carrying the damper and arrangedfor movement to remove the damper from the vibrator, and a pair ofyieldable jaws also carried-by said support and moved by the support, insaid movement thereof, past the vibrator, said jaws being separated byless than the dimension of the vibrator transverse to the direction ofsaid movement whereby to pluck the vibrator during said movement.

6. An exciter-damper device for use with a vibrator, said devicecomprising a loop of rigid material surrounding the vibrator in a planesubstantially normal to the vibrational axis of the vibrator, aresilient pad carried by the loop, a vibrator-accommodating opening insaid pad, means biasing the loop to a normal position wherein thevibrator is disposed within the opening in the pad, and means for movingthe loop a predetermined distance sufficient to remove the vibrator fromthe opening in the pad, said opening being provided with a constrictedaperture through which the vibrator may pass but which is normallyslightly smaller than the dimension of the vibrator transverse to thedirection of loop movement.

(References on following page) 17 References Cited in the file of thispatent 2,588,295 UNITED STATES PATENTS 2701414 254,910 Blake Mar. 14,1892 1,169,832 Johnson Feb. 1, 1916 5 922,777 1,824,706 Casciotta Sept.22, 1931 18 Rowe Mar. 4, 1952 Marshall May 3, 1955 FOREIGN PATENTSFrance June 18, 194-7

